Japanese Unexamined Patent Publication No. 2002-190360 discloses a connector wherein, in a FPC connector having a plurality of contacts which grip terminal portions of printed circuit boards, opposed gripping action contacts and fixed pieces are formed separately. In said connector, the gripping action contacts comprise two types of gripping action contacts with differing lengths, and gripping action contacts with differing lengths are placed so that they are adjacent to each other, so that the contact portions of the ends of the gripping action contacts are placed in a staggered manner. Additionally, fixed pieces affixed to the body at locations corresponding to each of the contact points are formed. The space between each of the opposing contact points is smaller than the thickness of a FPC, and when a FPC is inserted, there is a low insertion force (LIF) because of contact with each of the contact points. That is, after insertion, the FPC first comes into contact with a first contact point, and further, when inserted more deeply, it comes into contact with a second contact point, and is gripped by the elastic force of the gripping action contact at each contact point. In the next action, gripping action contacts with different lengths are elastically deformed by an actuator, in order to grip the FPC even more strongly.
However, according to this structure, when the inserted FPC is gripped, a pressing force due to the actuator is further added to the elastic force of the gripping action contacts, so that it becomes easy for warping to arise in the aforementioned FPC, and four parts, being the contact portions and fixed piece portions of the first and second contact points must be manufactured, so that an increase in manufacturing cost is incurred.
Additionally, Japanese Unexamined Patent Publication No. 2002-134194 discloses a connector wherein, in a FPC (flat cable) connector, there are two types of contacts being a first type and a second type separated and placed towards the anterior and posterior of the insertion direction, pressing portions provided for the first contacts, and driving portions (actuator) provided for the second contacts. The pressing portions are supported so that they can be brought closer to or separated from the first contacts provided to the anterior of the insertion direction, and they come into contact with the aforementioned FPC by being brought close to the aforementioned first contacts, and pushing the first contact points onto the first contacts. The driving portions contact the aforementioned FPC by being brought close to the second contacts provided to the posterior of the insertion direction, and by doing so, the second contact points are pressed onto the aforementioned second contacts, and simultaneously, the aforementioned pressing portions are driven and brought close to the first contacts.
A structure is disclosed wherein the contact points of the first and second contacts of the aforementioned connector are provided on the base side whereon the FPC is gripped, and so-called gripping at lower contacts is realized. In order to solve the problems of the conventional art that when a flat cable is inserted, the contacts are damaged, or that imperfect connection states can arise, and in order to solve the problem of the conventional art that since the operation of inserting a flat cable against a low resistance force is required, operability is inferior, in said connector, insertion can be done against the second contacts in the posterior of the insertion direction with no insertion force (Zero Insertion Force: ZIF), and insertion can be done against the first contacts in the anterior of the insertion direction with a low insertion force (Low Insertion Force: LIF).
However, at the present time, there is a demand for electrical connectors with various other shapes which realize industrial applicability, for example structures that are adapted for boards which are compatible with electrical connectors.